Re: [PATCH V4 00/27] C-SKY(csky) Linux Kernel Port

[Guo Ren]

Hello Stephen,

I'm Guo Ren from C-SKY and I'm working on csky linux port upstream.
I've prepared my git-tree based on linux-4.19-rc3:
git clone -b linux-next https://github.com/c-sky/csky-linux.git

Here is the pre-built cross compiler for fast test from our CI:
https://gitlab.com/c-sky/buildroot/-/jobs/97941896/artifacts/file/output/images/csky_toolchain_csky_ck860_platform_defconfig_72371bf75a51f27ea59fc34eeaf236e06b75bf69.tar.xz

You can also build newest gcc, binutils and they are upstreamed but not
released on gnu.org. Glibc is uptreaming now.

Please have a look and any feed back is welcome.

Best Regards
 Guo Ren

On Wed, Sep 12, 2018 at 04:30:36PM +0200, Arnd Bergmann wrote:
> On Wed, Sep 12, 2018 at 3:25 PM Guo Ren <ren_guo@xxxxxxxxx> wrote:
> >
> > This is the 3th version patchset to add the Linux kernel port for C-SKY(csky).
> > Thanks to everyone who provided feedback on the previous version.
> >
> > This patchset adds architecture support to Linux for C-SKY's 32-bit embedded
> > CPU cores and the patches are based on linux-4.18.4
> >
> > There are two ABI versions with several CPU cores in this patchset:
> >   ABIv1: ck610 (16-bit instruction, 32-bit data path, VIPT Cache ...)
> >   ABIv2: ck807 ck810 ck860 (16/32-bit variable length instruction, PIPT Cache,
> >          SMP ...)
> >
> > More information: http://en.c-sky.com
>
> This looks good to me overall. I think a good next step would be to get the port
> included in linux-next, by preparing a git tree with all the patches and asking
> Stephen Rothwell to include it there. Further comments on the architecture
> port itself can be done on top of the existing patches. I would suggest you
> base the git tree on an -rc release (either 4.19-rc1 or 4.19-rc3) and then never
> rebase again.
>
> You have included a couple of drivers in the submission: two timer and
> two irqchip drivers. Please leave those out for the moment, and either have
> them merged through the respective subsystem  trees, or get an Ack
> from the maintainers to merge them through your tree.
>
> I notice that a lot of the patches have no changeset comments on them.
> You should fix that and make a habit of describing every single patch
> with a few sentences, even if it seems obvious to you. Have a look at
> the changeset descriptions for the nds32 and riscv architectures when
> they got merged.
>
> One big question for me is what to do about time_t. Deepa and I are
> in the process of finalizing the system call ABI for 32-bit architectures
> with 64-bit time_t, but we are not done yet and it won't be complete
> for 4.20. If you target 4.21, that could be a chance to make csky the
> first architecture to only need the 64-bit time_t interface, with the
> corresponding user space changes.
>
>         Arnd